Overview

• The FDA’s decision grants full approval of Papzimeos for adult patients with recurrent respiratory papillomatosis who previously relied solely on repeated surgical debulking.
• In a single-arm, open-label Phase II trial of 35 adults, 18 (51%) achieved complete responses, defined as no need for surgical intervention for 12 months after treatment.
• Among those 18 responders, 15 evaluated at 24 months remained in complete response, demonstrating the therapy’s potential for durable disease control.
• Safety data showed no treatment-related serious or grade 3 or higher adverse events, with most participants experiencing only mild side effects such as injection site reactions, fatigue, chills and fever.
• Following the approval, Precigen began immediate promotion; shares surged more than 40% with CBER director Vinay Prasad defending the decision as proof that randomized trials may not always be required.